The present invention relates to herbicidal formulations of 2,4-dichlorophenoxy acetic acid (2,4-D). More particularly, the present invention concerns high-strength formulations of mixed 2,4-D salts that remain liquid at low temperature.
2,4-D is a known, effective herbicide. Various formulations are currently marketed, many of which are aqueous solutions that can be used as is or diluted prior to use. Typically the 2,4-D is provided as a salt, which exhibits sufficiently high solubility in water to provide a high-strength aqueous herbicidal formulation. A high-strength formulation is desirable for a variety of economic and environmental reasons. For example, it is desirable to provide a high-strength formulation to reduce shipping and handling costs and to reduce the amount of packaging material that must be disposed. The high-strength formulations should be stable and retain potency during storage and shipping. Furthermore, the high-strength formulation should be a clear, homogeneous liquid that is stable at ambient temperatures and should not exhibit any precipitation at temperatures as low as 0° C.
A major limitation of the dimethylamine (DMA) salt of 2,4-D is limited stability at low temperature and high concentration. For example, an aqueous formulation containing 625 grams acid equivalent per liter (gae/L) of the DMA salt of 2,4-D crystallizes at 0° C. The present invention addresses these needs and provides a wide variety of benefits and advantages.